Noble metal-free electrocatalysts have received widespread attention in a hydrogen evolution reaction (HER) due to the importance of renewable energy development. Herein, a Co₂P/CoP heterojunction embedded on an N-doped carbon (Co₂P/CoP/NC) electrocatalyst was prepared via an in situ pyrolysis method. The as-prepared electrocatalyst exhibited efficient electrocatalytic activity for HER in an acidic solution. The Co₂P/CoP/NC catalyst displayed an overpotential of 184 mV at 10 mA cm⁻² and a low Tafel slope of 82 mV dec⁻¹, which could be attributed to the tight Co₂P/CoP heterojunction and the synergetic effect of Co₂P/CoP and N-doped carbon. In addition, the electrochemical active surface area of Co₂P/CoP/NC was 75.2 m² g⁻¹, which indicated that more active regions can be applied for the HER process. This report may pave a new way for the design of efficient and low-cost N-doped-carbon-supported 3d transition metal phosphide electrocatalysts.